U.S. patent application number 11/505741 was filed with the patent office on 2007-05-17 for method and apparatus for wet treatment of textiles and textile articles at low temperatures.
Invention is credited to Wei Chen, Ching-Yee Lung, Xiao-Ming Tao.
Application Number | 20070107136 11/505741 |
Document ID | / |
Family ID | 38039215 |
Filed Date | 2007-05-17 |
United States Patent
Application |
20070107136 |
Kind Code |
A1 |
Tao; Xiao-Ming ; et
al. |
May 17, 2007 |
Method and apparatus for wet treatment of textiles and textile
articles at low temperatures
Abstract
The invention provides a method and apparatus of applying
ultrasound energy in wet treatment of textiles, particularly in a
dyeing process. By keeping the articles to be dyed within an
optimal zone of the sonoreactor, the method achieves a high dyeing
efficiency, making it possible to dye at a low temperature, with
little or no use of chemical assistants while achieve a dyeing
quality comparable with conventional dyeing method relying on high
temperatures and/or use of chemical assistants. The apparatus
suitable for practicing the method uses a conveyor belt having two
layers of meshes between the articles to be dyed are sandwiched
exerting no tension on the articles. The conveyor belt can be
configured to travel within the optimal zone of the sonoreactor,
whereby constraining the articles under dyeing within the optimal
zone. With such a conveyor belt, small pieces of articles can be
dyed just as easily as the large ones.
Inventors: |
Tao; Xiao-Ming; (Hong Kong,
CN) ; Chen; Wei; (Hong Kong, CN) ; Lung;
Ching-Yee; (Hong Kong, CN) |
Correspondence
Address: |
COOPER & DUNHAM, LLP
1185 AVENUE OF THE AMERICAS
NEW YORK
NY
10036
US
|
Family ID: |
38039215 |
Appl. No.: |
11/505741 |
Filed: |
August 16, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60708763 |
Aug 17, 2005 |
|
|
|
Current U.S.
Class: |
8/115.51 |
Current CPC
Class: |
C11D 11/007
20130101 |
Class at
Publication: |
008/115.51 |
International
Class: |
C11D 3/00 20060101
C11D003/00 |
Claims
1. A method for wet-treatment of textile or a textile article,
comprising the steps of (a) adding a treatment solution in a
container, (b) operating at least one sonoreactor located in or
near said container, and (c) substantially confining textile or
textile article to be wet-treated in said solution during wet
treatment within a zone in said container where vigorous
cavitations are generated by said sonoreactor; said steps (a)-(c)
being performed in any order suitable for performing wet
treatment.
2. The method of claim 1, wherein said wet-treatment is for
coloration and said treatment solution comprises a dye.
3. The method of claim 2, wherein said sonoreactor is operating at
a frequency equal to or lower than 25 KHz and, other than the heat
generated by said sonoreactor during operation, no heating is
employed.
4. The method of claim 1, wherein the temperature of said treatment
solution during wet treatment is lower than 80.degree. C.
5. The method of claim 4, wherein the temperature of said treatment
solution is lower than 70.degree. C.
6. The method of claim 1, wherein a conveyor belt is used for
confining said textile or textile article within said zone in said
container.
7. The method of claim 1, wherein a net having a fixed location in
said container is used for confining said textile or textile
article within said zone in said container, said net allowing said
textile or textile article to contact with said treatment solution
but constraining it within said zone.
8. The method of claim 6, wherein said conveyor belt comprises at
least two layers of meshes between which said textile or textile
article is contained.
9. The method of claim 1, wherein two or more sonoreactors are
used, which operate at a same frequency or different
frequencies.
10. The method of claim 3, further comprises a step of pre-treating
said textile or textile article with a swelling agent.
11. An apparatus, comprising a container adapted for containing a
treatment solution for wet-treatment of textile or textile
articles, a constraint adapted for constraining textile or textile
articles within a particular location in said container, and a
sonoreactor positioned for generating cavitations in said
particular location in said container.
12. The apparatus of claim 11, wherein said apparatus is used for
coloration of textile or textile articles.
13. The apparatus of claim 11, wherein said sonoreactor is adapted
for operating at a frequency equal to or lower than 25 kHz.
14. The apparatus of claim 11, wherein said constraint is a
conveyor belt.
15. The apparatus of claim 11, wherein said constraint is a net
fixed in a location within said container.
16. The apparatus of claim 14, wherein said conveyor belt comprises
two layers of meshes between which said textile or textile articles
are confined.
17. The apparatus of claim 16, wherein said apparatus is for
coloration of textile or textile articles.
18. The apparatus of claim 17, further comprising a pretreatment
unit.
19. The apparatus of claim 18, wherein said pretreatment unit is
for applying a swelling agent to said textile or textile
articles.
20. The method of claim 1, wherein said wet-treatment is for
textile finishing.
21. The method of claim 20, wherein said textile finishing is
surface treatment or particle functionalization.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] Pursuant to 35 U.S.C. .sctn. 119(e), this application claims
priority to U.S. Provisional Application No. 60/708,763, filed Aug.
17, 2005, the contents of which are hereby incorporated by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a process of wet-treatment
of textile and textile articles. Particularly, it relates to a low
temperature wet treatment process and equipment suitable for
coloring a variety of textile and textile articles, such as natural
or synthetic fibers, yams, fabrics, garments (larger or small),
using a novel configuration that maintaining the articles under
treatment staying and/or moving within optimal dyeing zones of one
or more ultrasonic generators.
BACKGROUND OF THE INVENTION
[0003] The wet treatment process assisted with ultrasound energy
has been employed or suggested for textile coloration. In practice,
however, the efficacy of coloration is often limited due to
unevenness of cavitations formed in dyeing equipment, such as, a
common ultrasonic bath. To compensate the lack of cavitation
uniformity, methods such as heating or using auxiliary chemicals
have been used in the dyeing process assisted by ultrasound
generators (or transducers), which themselves may also need to
operate at higher frequencies to achieve a satisfactory efficacy.
Thus, the conventional textile dyeing treatment is a major wet
process which consumes much energy and water and releases large
quantities of effluent to the environment. High temperature, high
pressure or auxiliary chemicals are needed especially for those
synthetic fabrics such as polyester, causing serious pollution
problems and consumption of a large amount of energy, thereby
increasing the cost of production. There is another disadvantage
because, at high temperatures, it is difficult to dye those
natural/synthetic blend textiles, such as cotton or wool/polyester
blends. Furthermore, increasingly stringent environmental
legislations and a much more competitive market demand new
efficient methods for coloration in the textile industry.
[0004] Although over the years some progress has been made, there
remain great challenges for substantially and effectively achieving
energy savings by dyeing textiles at a low temperature, for
reducing processing times, and for causing few environmental
problems with reduced consumption of auxiliary chemicals, etc. For
example, in U.S. Pat. No. 6,381,995, microwave irradiation was
applied to the goods undergoing coloration, in order to heat them
to about 100-130.degree. C. under a low bath ratio, tensionless,
and short-term dyeing process. U.S. Pat. No. 5,512,062 describes a
method, apparatus, and related dye compositions for dyeing textiles
which operates at high pressures, is open to the atmosphere, and
does not require the steaming of the textile to set or fix the dye
to the textile; specifically, a multi-temperature textile dyeing
method (between 70-120.degree. C.) which achieves a more complete
and even dyeing of the textile in a shorter period of time. In U.S.
Pat. No. 5,540,740, a micro-emulsion dyeing process for polyester
fibers was explored by adding dyestuff and a dye solubility
assistant agent selected from the group of short chain alcohols,
dyeing polyester fibers at room temperature for 1-3 hours, washing
the polyester fibers with a nonionic washing agent and thereafter
drying the dyed polyester fibers. In U.S. Pat. No. 5,571,291,
low-temperature dyeing additives for protein fiber products were
used and served to relax the higher-order structures of the protein
fibers before dyeing or during dyeing, to thereby swell the fibers,
thus rendering the fibers readily dyeable without being detriment
to the properties thereof.
[0005] There are a few patents related to the ultrasound-aided
dyeing processing. European Pat. No. EP0373119 describes a process
and apparatus for preparing a dye solution in textile coloration,
in particular for reactive and vat dyes of various solubility. A
high color yield was claimed. It covers a process of preparing the
dyeing solution and a device to do it. The application of
ultrasonic reactors is not during the dyeing or wet treatment
processes. Thus the apparatus is a preparation unit added to the
dyeing bath. The dyeing solution is heated to 30-80.degree. C. In
U.S. Pat. No. 4,419,160, ultrasound technology is used for
thermoplastic non-woven fabric dyeing. The ultrasonically bonded
point bonds of non-woven fabric are dyed by applying liquid dye to
the contacting crossing points of the fibers before or at the same
time that they are bonded by the application of ultrasonic energy,
such energy being used not only to effect the point bonds but also
to drive and fix the dye in such point bonds. That invention was
focused on the dyeing of non-woven fabrics and more particularly,
to the dyeing of fabric made of ultrasonically fusible fibers and
fabrics.
[0006] Ahmad WYW and Saligram AN reported the low-temperature
dyeing of polyester fabric using ultrasound. For details, see
Ahmad, M. Y. W, and M. Lomas, "The low-temperature dyeing of
polyester fabric using ultrasound", Journal of Society of Dyers and
Colorists, 112(9), 245-248 (1996) and Saligram, A. N., S. R.
Shukla, and M. Mathur, "Dyeing of polyester fiber using
ultrasound", Journal of the Society of Dyers and Colorists, 109,
263-266 (1993). The advantages of being able to dye or print
polyester fabrics at temperatures of 50.degree. C., particularly
for such methods as batik printing where wax is used, are
discussed. Polyester fabrics were dyed in an ultrasonic bath using
3 disperse dyes. However, their results were not encouraging: the
fabrics obtained were not generally as good as those that can be
obtained in conventional high-temperature processes.
[0007] As mentioned in the above, ultrasound has been used in
textile coloration. However, due to the problem of directional
sensitivity of the sonoreactor, the active cavitational volume is
not evenly distributed throughout the dyeing bath, with strong
cavitations in areas close to the surface of the sonoreactor while
less cavitations in most other areas. In order to have sufficient
coloration in all the areas within the dyeing bath, it is necessary
to increase the operating frequency of sonoreactor, increase the
temperature, increase the process time, and/or add auxiliary
chemicals. Thus, there is a need for new ways of applying
ultrasonic energy to wet textile treatment.
SUMMARY OF THE INVENTION
[0008] One object of the present invention is providing an
ultrasound energy assisted wet processing method for textile
coloration, which requires low temperatures, low energy
consumption, low or no auxiliary chemicals, and/or short processing
time, and at the same time maintains a satisfactory quality of
coloration. This invention, using a constraining net to keep the
articles under coloring either staying (in a batch mode) or
continuously traveling (in a continuous mode) within optimal zones
where ultrasonic cavitations are the most vigorous, brings the
ultrasound into play to a much greater extent so that articles can
be dyed under lower energy consumption and higher efficiency. The
design of the constraining net (attached in the bath or on the
conveyor belt) can be based on the types of articles under dyeing
and it is within ordinary skill of the people in the art to make a
constraining net or other means that can confine the articles under
coloring staying or moving in the optimal zone of the sonoreactor.
Similarly, the sonoreactor can be conventional ones or ones with
specific configurations according to the requirements under
particular situations. People of ordinary skill in the art are
capable of determining the location of the optimal zone for dyeing
and the route taken by the conveyor around the sonoreactor, which
obviously varies in each particular situation. Location of the
optimal zone depends on the ultrasound system employed. For
example, because the location of transducers and geometric
configuration of the ultrasound bath are fixed, the optimal
distance from the sonoreactor's surface is localized at the middle
of the container based on the propagation and reflection of the
ultrasound waves in the bath. Also, the density of the medium
undergoes periodic alterations with regions of alternating
compression and rarefaction. In the examples described below, a
relative agile sonoreactor was used, which is an ultrasound horn.
The horn was immersed under the liquid medium at approximately 2 cm
depth. Compared with the ultrasound bath, the geometry and space of
the container (an experimental cell) with textile samples, was
unfixed. The optimal zone should be between the bottom of cell and
the tip of the horn depending on the capacity of the cell.
Therefore, the conveyor belt with textiles could be raised or
lowered to adjust the distance between the bottom of the cell and
the tip of the horn.
[0009] The method of this invention is applicable to various
textile materials, including synthetic, natural fabrics and their
blends. By reducing the dyeing temperature, processing time and
chemical consumption, the fabrics after dyeing possess qualities of
better fastness, touch, air permeability and elasticity. In
addition, the method of the present invention has applications
other than textile coloration. It is useful for textile finishing,
such as, reduction of surface crystallinity of polymeric textile
materials and surface functionalization of textiles by doping or
coating with nanomaterials at low temperature, etc.
[0010] The various features of novelty which characterize the
invention are pointed out with particularity in the claims annexed
to and forming a part of this disclosure. For a better
understanding of the invention, its operating advantages, and
specific objects attained by its use, reference should be made to
the drawings and the following description in which there are
illustrated and described preferred embodiments of the
invention.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIGS. 1 and 2 show the pictures taken from the polyester
fabrics dyed under ultrasound according to the present invention
and conventional methods.
[0012] FIGS. 3 and 4 show the pictures of cotton and linen fabrics
dyed under ultrasound according to the present invention and
conventional methods.
[0013] FIG. 5 shows the picture of wool fabrics dyed under
ultrasound according to the present invention and a conventional
method.
[0014] FIG. 6 depicts ultrasound-assisted dyeing apparatus with
single ultrasonic source arranged according to the present
invention.
[0015] FIG. 7 depicts ultrasound-assisted dyeing apparatus with
multiple ultrasonic sources arranged according to the present
invention.
[0016] FIG. 8(a) is an enlarged section view of the sandwich
structure of the conveyor as shown in FIGS. 6 and 7, while FIG.
8(b) is the top view of a typical mesh layer of the conveyor.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0017] In the embodiment described below, ultrasound dyeing was
performed in a batch mode, as opposed to a continuous mode. The
high efficiency of ultrasound assisted process of the present
invention is accomplished by arranging and distributing single or
multiple-ultrasonic transducers to a container filled with a dye
solution comprising sufficient amount of water, in which the dyed
goods can be immersed completely. Through some routine testing
which can be conducted with ordinary skill in the art, the number,
location, and combination of operating frequency and power of the
ultrasonic transducers are particularly configured relative to the
size and dimensions of the dye container so that entire dye
solution is substantially within an optimal zone where cavitations
are sufficiently vigorous and uniform for efficient and low
temperature dyeing or other types of fabric treatments. The
treatment system, which is open to the air, is subjected to
irradiating ultrasound below 25 KHz. Pretreatment with/without
swelling agents may be optionally carried out before dyeing,
depending on the characteristics of different textile materials to
be treated.
[0018] In the testing examples described below, a typical lab-scale
setup was used. The bath was a 100 mL beaker or an experimental
cell; the solution was 100 mL; Ultrasound, with a frequency of 25
kHz, was introduced into the reactive liquid with a titanic alloy
horn with power output adjustable between 0-900 W (JY92-2D, NINBO
SCIENTZ BIOTECHNOLOGY CO., LTD). The ultrasound horn was positioned
in the bath supported by bracket which also is commercially
available.
[0019] Several different dyes for synthetic and nature fabric were
surveyed to determine the best potential applications of ultrasound
in terms of dyes, chemicals, processes, and machines. It was
determined, for example, that dispersed dye was used for polyester,
direct dye for cotton and linen, and acid dye for wool. Before the
ultrasound assisted dyeing process, polyester, cotton and linen
fabrics were optionally pretreated by padding with a swelling
agent. For comparison, conventional dyeing method for each type was
also conducted.
[0020] The ultrasonic dyeing process was performed with no heating.
The temperature of the dye solution may increase due to ultrasound
cavitations. Depending on the employed ultrasound intensity,
ultrasonic irradiation time and dye solution volume, the
temperature was in the range of 50-70.degree. C.
Ultrasound-assisted Dispersed Dyeing for Polyester Fabric
[0021] Ultrasound assisted dispersed dyeing for polyester fabric
was conducted under ambient condition. In the dyeing solution, the
ratio of dispersed dyes to the article to be dyed was 1:50. The
operating frequency and intensity of the ultrasound employed were
25 KHz and 850 W, respectively, and the irradiation time is in the
range of 20-30 minutes. Solution temperature arose by the
cavitation was in the range of 60-70.degree. C.
[0022] For comparison, a conventional dispersed dyeing process was
conducted at a high temperature, either at 90.degree. C. with
carrier for 30 minutes or at 130.degree. C. with pressure for 30
minutes. In the dyeing solution, the ratio of dispersed dyes to
goods to be dyed is the same with that for ultrasound dyeing (i.e.,
1:50), the ratio of dispersing agent to dye is 6:1, carrier to dye
is 30:1, and acetic acid to dye is 3:1.
[0023] FIG. 1 shows the pictures taken from the polyester fabrics
dyed under ultrasound and conventional methods, comparing the
dyeing effect of both methods. For the ultrasound dyeing conducted
in the dyeing solution, the ratio of dispersed dyes to the article
to be dyed was 1:50. For the conventional dyeing conducted in the
dyeing solution, the ratio of dispersed dyes to the article to be
dyes is the same with that one for ultrasound dyeing. In addition,
a dispersing agent, carrier and acetic acid were added. The ratios
to dye are 6:1, 30:1 and 3:1 respectively. The left side (sample C)
is the polyester fabric with ultrasound dyeing method with no
heating for 20 minutes according to the present invention while the
right side (sample A) is polyester fabric dyed with the
conventional method with carrier at 90.degree. C. for 30 minutes.
In FIG. 2, a higher dye concentration was used: two times of
concentration as used FIG. 1, that is, the ratio of dispersed dyes
to the article to be dyed was 1:25. When dyeing under conventional
method, the ratios of dispersing agent, carrier and acetic acid to
dye kept the same as with the conventional method used in FIG. 1.
Again, the left side (sample D) is polyester fabric, dyed with the
ultrasound method, no heating for 20 minutes, and the right side
(sample B) is with the conventional method with carrier heated to
130.degree. C. for 30 minutes. Table 1 provides the color values of
the dyed fabrics (i.e., samples A, B, C and D) under conventional
and ultrasound dyeing conditions. TABLE-US-00001 TABLE 1 Color
values of the polyester fabrics dyed under ultrasound and
conventional methods Sample Code FABRIC X Y Z A Polyester-Carrier
9.540 9.812 31.163 B Polyester-HT130.degree. C. 7.245 7.068 25.629
C Polyester-Ultrasound 9.496 9.764 31.830 D Polyester-Ultrasound/H-
5.227 4.782 18.773 concentration
[0024] X, Y, Z are tristimulus values used to define colors. If two
colors have the same tristimulus values, they will look alike under
the same viewing conditions by a normal observer. For A, B & C,
(Polyester-Carrier, Polyester-HT1300C & Polyester-Ultrasound)
the three dyed fabrics have almost the same X, Y, Z values
indicating that color of the fabrics under conventional and
ultrasound dyeing look alike. But for D
(Polyester-Ultrasound/H-concentration) the X, Y & Z values are
significantly different from that of A, B & C, this means that
absorption rate is increased when the ultrasound dyeing is carried
out under high dyes concentration.
Ultrasound-Assisted Direct Dyeing for Cotton and Linen Fabrics
[0025] Ultrasound assisted dyeing with disperse dyes for cellulose
fabrics such as cotton and linen were conducted. In the dyeing
bath, the ratio of dispersed dyes to fabric goods is 1:50 or more.
Frequency and intensity of the ultrasound employed in this
experiment were less than 25 KHz and 850 W respectively, and the
ultrasound irradiating time was 20 minutes. The solution
temperature arose by the cavitation was in the range of
60-70.degree. C.
[0026] For comparison, a conventional direct dyeing method was
conducted at 95.degree. C. for 30 minutes. In the dyeing solution,
the ratio of dispersed dyes to the goods to be dyed is the same as
for ultrasound dyeing (i.e., 1:50), the ratio of common salt to dye
is 10:1, and soda ash to dye is 0.25:1.
[0027] FIG. 3 shows the dyeing effect of ultrasound-assisted
compared with the conventional direct dyeing method. The left side
is the cotton fabric with the ultrasound dyeing method without
heating for 20 minutes and the right side is the cotton fabric with
conventional method at 95.degree. C. for 30 minutes. FIG. 4 shows
the dyeing effect of ultrasound-assisted compared with the
conventional direct dyeing method. The left side is the linen
fabric with ultrasound dyeing method without heating for 20
minutes; the right side is the linen fabric with the conventional
method at 95.degree. C. for 30 minutes.
[0028] Table 2 presents the color values of the dyed fabrics under
conventional and ultrasound dyeing conducted similarly as in FIGS.
3 and 4 (except that the temperature was 98.degree. C., instead of
95.degree. C.). The results shown in FIGS. 3 and 4 and Table 2 all
demonstrate that, for the both cotton and linen, the ultrasound
dyeing with shorter time according to the present invention can
give the same effect as the conventional ones with a higher
temperatures and a longer time. TABLE-US-00002 TABLE 2 Color values
of the cotton and linen fabrics dyed under ultrasound and
conventional methods. Sample Code FABRIC X Y Z E Cotton-98.degree.
C. 19.079 21.743 47.964 F Cotton-Ultrasound 18.742 21.485 47.044 G
Linen-98.degree. C. 20.904 24.220 45.945 H Linen-Ultrasound 20.026
23.137 44.407
Ultrasound-Assisted Acid Dyeing for Wool Fabric
[0029] Ultrasound assisted dyeing with acid dyes for wool fabric
was conducted. In the dyeing solution, the ratio of dispersed dyes
to goods to be dyed is 1:50. Frequency and intensity of the
ultrasound employed in this experiment are 25 KHz and 850 W
respectively, and the ultrasound irradiating time is 20 min. The
solution temperature arose by the cavitation was in the range of
60-70.degree. C.
[0030] For comparison, a conventional acid dyeing method was
conducted at a high temperature, at about 98.degree. C. for 30
minutes. In the dyeing solution, the ratio of dispersed dyes to
goods to be dyed is the same as for ultrasound dyeing (i.e., 1:50),
sulphuric acid to dye is 1.5:1, and glauber's salt to dye is
5:1.
[0031] FIG. 5 shows the pictures of wool fabrics dyed under
ultrasound compared with the conventional method. Table 3 presents
the color values of the dyed wool fabrics under conventional and
ultrasound dyeing. The results shown in FIG. 5 and Table 3 all
demonstrate that the ultrasound dyeing process of the present
invention with shorter time can give the same effect as the
conventional method for a longer time at a high temperature.
TABLE-US-00003 TABLE 3 Color values of the wool fabrics dyed under
ultrasound and conventional methods. Sample Code FABRIC X Y Z I
Wool-98.degree. C. 5.087 5.277 18.924 J Wool-Ultrasound 4.808 4.823
18.167
[0032] This is a great advantage offered by the present invention:
a low temperature process (generally in the range of 50-70.degree.
C.) suitable for various types of fabric, including but not limited
to, polyester, cotton, linen, wool. This low temperature
ultrasound-assisted process achieves as satisfactory results as
achievable by the conventional dyeing methods at near or above the
boiling temperature. The dyeing process of the present invention
can be further enhanced by pre-swelling the fabric in terms of
reduced temperature, lower processing time and less need for
chemicals. In addition, the dyeing process of the present invention
allows real-time control of color shade by varying irradiation time
as desired.
Ultrasound-Assisted Treatment Apparatus
[0033] While conventional sonoreactor may be used for practicing
the present invention and the construction of the sonoreactor is
not part of the present invention, design of large-scale
sonoreactors may take into consideration of the specifics peculiar
to the wet-treatment process of the present invention, for example,
the need to confine the articles under treatment within an optimal
zone where the sonoreactor provides severe and uniform conditions
of cavitation and at the same time operates at relatively lower
frequencies, for example, less than 25 KHz. Nonetheless, this
special consideration is within ordinary skill of the person
skilled in the art. A single and multiple conventional transducers
(different combinations of operating frequency and power)
ultrasound dyeing machines were successfully used for operating in
a batch mode or in a continuous mode, as shown in FIGS. 6-8, where
the garments/fabrics/yarns/fibers can be maintained in a
tensionless state during wet treatment.
[0034] FIG. 6 depicts ultrasound-assisted dyeing apparatus with
single ultrasonic source wherein: Zone A is the main body of the
dyeing apparatus with an ultrasonic horn 13. Zone B is for
pretreatment where the fibers/yarns/fabrics/garments to be dyed are
immersed in a swelling agent solution and then squeezed before
going to the dyeing process in Zone A. Further, in Zone B', the
fibers/yarns/fabrics/garments can be additionally or alternatively
sprayed with one or more swelling agents and squeezed before going
to the dyeing process in Zone A. Different processes may be
performed according to the type of the articles to be dyed. For
example, a swelling pretreatment may be performed using either Zone
B or B'. Or, no pretreatment is needed.
[0035] The apparatus shown in FIG. 6 is suitable for dyeing a small
amount of goods in batch as well as in a continuous mode, in which
the fibers/yams/fabrics/garments to be dyed are enveloped and
sandwiched (FIG. 8a) between meshes (FIG. 8b) without exerting any
tension on the articles under dyeing. Referring to FIG. 6, the
numerical references 1 and 12 are driven rollers; 2-4 and 6-11 are
guide rollers; 5 and 5' are squeezing rollers; 13 is an ultrasonic
horn (<25 KHz, power up to 900 W).
[0036] FIG. 7 shows another ultrasound-assisted dyeing apparatus
with multiple ultrasonic sources suitable for practicing the
present invention. Zone A is the main body of the dyeing apparatus
with multiple ultrasonic transducers 1, on both sides. Zone B is
the place where the fibers/yarns/fabrics/garments to be dyed are
immersed in a solution containing swelling agents and then squeezed
before going to the dyeing process. Zone B' is an additional or
alternative unit to spray the swelling agent to the
fibers/yarns/fabrics/garments prior to being dyed in Zone A.
Pretreatments using either Zone B or B' will be performed according
to the type of articles to be dyed. Although pretreatment was used
in the particular embodiments shown above, it is optional. In
general, for polyester, cotton and linen fabrics the swelling
pretreatment may be used to achieve better results. For wool
fabrics, on the other hand, such pretreatment may not enhance the
result significantly.
[0037] The apparatus shown in FIG. 7 is suitable for dyeing a large
amount of goods in batch as well as in a continuous mode. The
fibers/yarns/fabrics/garments to be dyed are enveloped and
sandwiched between meshes without any tension exerted to them as
shown in FIG. 8. The numerical reference 1 refers to combinations
of several ultrasonic transducers distributed on two sides of
quadrate dyeing bath. 2-10, and 12-14 are guide rollers; 11 and 11'
are squeezing rollers; and 15 is a driven roller.
[0038] FIG. 8a is a cross-section view of the sandwich structure of
the conveyor as used in FIGS. 6 and 7, showing that the
fibers/yarns/fabrics/garments are enveloped and sandwiched between
two layers of meshes without exerting any tension. FIG. 8 (b) is
the top view of a typical mesh example.
[0039] With the method of the present invention, as described
above, ultrasound energy is substantially and efficiently employed
as a substitute either in whole or in part for the conventional
needs of higher dyeing temperature, longer dyeing time and uses of
chemical assistants. The method and apparatus lead to significantly
reduce the dye temperature (50-70.degree. C.) processing time, and
consumption of auxiliary chemicals without degrading the coloration
effect. Although the particular examples are for textile
coloration, it can easily be understood by people with ordinary
skill in the art that the method is applicable to other types of
wet treatment of textiles. In summary, with the easy and generally
applicable method and device of the present invention, natural and
synthetic fibers/yarns/fabrics/garments may all be dyed (or
undergone other types of wet treatment) at lower costs, thereby
increasing industry competitiveness and meeting the market
demand.
[0040] As used in this application, the article "a" means "one or
more" unless it is specified otherwise, and the terms "sonoreactor"
and "ultrasonic transducer" are used interchangeably. The term
"textile" here means any fibers, yarns, fabrics or cloth, which are
natural, synthetic or blend thereof, and "textile article" means
any articles or goods made of textile as specially defined here.
Examples of textile articles are garments and stuffed toys.
[0041] While there have been described and pointed out fundamental
novel features of the invention as applied to a preferred
embodiment thereof, it will be understood that various omissions
and substitutions and changes, in the form and details of the
embodiments illustrated, may be made by those skilled in the art
without departing from the spirit of the invention. The invention
is not limited by the embodiments described above which are
presented as examples only but can be modified in various ways
within the scope of protection defined by the appended patent
claims.
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